TeaSound, the Freesound client for iPad, although it isn’t free (as Freesound is).
Freesound is the largest online repository of permissively licensed audio. TeaSound helps you search and collect audio from Freesound. Great for foley sounds for movies, samples and loops for song production, any all kinds of other projects!
TeaSound currently requires a free Dropbox account for collecting audio. When you find a sound you like you can save it to your Dropbox, where it will be instantly synced to your Mac or PC.
All the sounds you’ll find using TeaSound are licensed under a Creative Commons License, and are available for use in your project!